Recently, a significant decrease of total serum iron and serum ferritin concentrations related with an increase of serum IL-6 concentration has been observed in pregnant women and in hemodialysis patients, orally treated with ferrous sulfate. Therefore, it can be hypothesized that supplemented iron was not exported from cells to circulation, but it was accumulated inside the cells, thereby increasing inflammatory status, similarly to that reported in animals treated with ferrous sulfate.